Wireless power transfer system for elevators with extended range

ABSTRACT

A wireless power transfer system for wirelessly powering a conveyance apparatus of a conveyance system including: a wireless electrical power transmitter located along a side of the conveyance system in a first location, the side being stationary; and a wireless electrical power receiver located along a surface of the conveyance apparatus opposite the side, the wireless electrical power receiver and the wireless electrical power transmitter being in a facing spaced relationship defining a gap therebetween when the wireless electrical power receiver is located at the first location.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/779,511 filed Dec. 14, 2018, which is incorporated herein byreference in its entirety.

BACKGROUND

The embodiments herein relate to the field of conveyance systems, andspecifically to a method and apparatus for powering a conveyance system.

Conveyance systems, such as, for example, elevator systems, escalatorsystems, and moving walkways require electric power for operation.Travelling cables typically connect an elevator car of the elevatorsystem to a stationary power source to provide power to the elevatorcar. Travelling cables add expense, weight, and complexity to elevatorcar operation and installation, thus improved methods of poweringelevator cars are desired.

BRIEF SUMMARY

According to an embodiment, a wireless power transfer system forwirelessly powering a conveyance apparatus of a conveyance system isprovided. The wireless power transfer system including: a wirelesselectrical power transmitter located along a side of the conveyancesystem in a first location, the side being stationary; and a wirelesselectrical power receiver located along a surface of the conveyanceapparatus opposite the side, the wireless electrical power receiver andthe wireless electrical power transmitter being in a facing spacedrelationship defining a gap therebetween when the wireless electricalpower receiver is located at the first location.

In addition to one or more of the features described herein, or as analternative, further embodiments may include: a magnetic field enhancerlocated within the gap, the magnetic field enhancer being configured toextend a wireless power transfer range of the wireless electrical powertransmitter.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the conveyance systemis an elevator system and the conveyance apparatus is an elevator car.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the side is a wall ofan elevator shaft of the elevator system.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer further includes a metamaterial block.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the metamaterial blockincludes at least one of a spiral resonator and a split ring resonator.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer further includes an array of resonators.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is located closer to the wireless electrical power transmitterthan the wireless electrical power receiver.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is located closer to the wireless electrical power receiverthan the wireless electrical power transmitter.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is shaped to wrap at least partially around the wirelesselectrical power transmitter.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is shaped to wrap at least partially around the wirelesselectrical power receiver.

According to another embodiment, a conveyance system is provided. Theconveyance system including: a conveyance apparatus; and a wirelesspower transfer system for wirelessly powering the conveyance apparatusof the conveyance system, the wireless power transfer system including:a wireless electrical power transmitter located along a side of theconveyance system in a first location, the side being stationary; and awireless electrical power receiver located along a surface of theconveyance apparatus opposite the side, the wireless electrical powerreceiver and the wireless electrical power transmitter being in a facingspaced relationship defining a gap therebetween when the wirelesselectrical power receiver is located at the first location.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the wireless powertransfer system further includes: a magnetic field enhancer locatedwithin the gap, the magnetic field enhancer being configured to extend awireless power transfer range of the wireless electrical powertransmitter.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the conveyance systemis an elevator system and the conveyance apparatus is an elevator car.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the side is a wall ofan elevator shaft of the elevator system.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer further includes a metamaterial block.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the metamaterial blockincludes at least one of a spiral resonator and a split ring resonator.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer further includes an array of resonators.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is located closer to the wireless electrical power transmitterthan the wireless electrical power receiver.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is located closer to the wireless electrical power receiverthan the wireless electrical power transmitter.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is shaped to wrap at least partially around the wirelesselectrical power transmitter.

In addition to one or more of the features described herein, or as analternative, further embodiments may include that the magnetic fieldenhancer is shaped to wrap at least partially around the wirelesselectrical power receiver.

Technical effects of embodiments of the present disclosure includepowering elevator cars of an elevator system wirelessly and expandingthe transmission range that an elevator car can receive wireless powerutilizing a magnetic field enhancer.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, that the followingdescription and drawings are intended to be illustrative and explanatoryin nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements.

FIG. 1 is a schematic illustration of an elevator system that may employvarious embodiments of the present disclosure;

FIG. 2 is a schematic illustration of a wireless power transfer systemfor the elevator system of FIG. 1, in accordance with an embodiment ofthe disclosure;

FIG. 3 is an enlarged view of the wireless power transfer system of FIG.2, in accordance with an embodiment of the disclosure;

FIG. 4 is an enlarged view of the wireless power transfer system of FIG.2 having a magnetic field enhancer, in accordance with an embodiment ofthe disclosure;

FIG. 5 is an enlarged view of the wireless power transfer system of FIG.2 having a magnetic field enhancer, in accordance with an embodiment ofthe disclosure; and

FIG. 6 is an enlarged view of the wireless power transfer system of FIG.2 having a magnetic field enhancer, in accordance with an embodiment ofthe disclosure.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of an elevator system 101 including anelevator car 103, a counterweight 105, a tension member 107, a guiderail 109, a machine 111, a position reference system 113, and acontroller 115. The elevator car 103 and counterweight 105 are connectedto each other by the tension member 107. The tension member 107 mayinclude or be configured as, for example, ropes, steel cables, and/orcoated-steel belts. The counterweight 105 is configured to balance aload of the elevator car 103 and is configured to facilitate movement ofthe elevator car 103 concurrently and in an opposite direction withrespect to the counterweight 105 within an elevator shaft 117 and alongthe guide rail 109.

The tension member 107 engages the machine 111, which is part of anoverhead structure of the elevator system 101. The machine 111 isconfigured to control movement between the elevator car 103 and thecounterweight 105. The position reference system 113 may be mounted on afixed part at the top of the elevator shaft 117, such as on a support orguide rail, and may be configured to provide position signals related toa position of the elevator car 103 within the elevator shaft 117. Inother embodiments, the position reference system 113 may be directlymounted to a moving component of the machine 111, or may be located inother positions and/or configurations as known in the art. The positionreference system 113 can be any device or mechanism for monitoring aposition of an elevator car and/or counter weight, as known in the art.For example, without limitation, the position reference system 113 canbe an encoder, sensor, or other system and can include velocity sensing,absolute position sensing, etc., as will be appreciated by those ofskill in the art.

The controller 115 is located, as shown, in a controller room 121 of theelevator shaft 117 and is configured to control the operation of theelevator system 101, and particularly the elevator car 103. For example,the controller 115 may provide drive signals to the machine 111 tocontrol the acceleration, deceleration, leveling, stopping, etc. of theelevator car 103. The controller 115 may also be configured to receiveposition signals from the position reference system 113 or any otherdesired position reference device. When moving up or down within theelevator shaft 117 along guide rail 109, the elevator car 103 may stopat one or more landings 125 as controlled by the controller 115.Although shown in a controller room 121, those of skill in the art willappreciate that the controller 115 can be located and/or configured inother locations or positions within the elevator system 101. In oneembodiment, the controller may be located remotely or in the cloud.

The machine 111 may include a motor or similar driving mechanism. Inaccordance with embodiments of the disclosure, the machine 111 isconfigured to include an electrically driven motor. The power supply forthe motor may be any power source, including a power grid, which, incombination with other components, is supplied to the motor. The machine111 may include a traction sheave that imparts force to tension member107 to move the elevator car 103 within elevator shaft 117.

Although shown and described with a roping system including tensionmember 107, elevator systems that employ other methods and mechanisms ofmoving an elevator car within an elevator shaft may employ embodimentsof the present disclosure. For example, embodiments may be employed inropeless elevator systems using a linear motor to impart motion to anelevator car. Embodiments may also be employed in ropeless elevatorsystems using a hydraulic lift to impart motion to an elevator car. FIG.1 is merely a non-limiting example presented for illustrative andexplanatory purposes.

In other embodiments, the system comprises a conveyance system thatmoves passengers between floors and/or along a single floor. Suchconveyance systems may include escalators, people movers, etc.Accordingly, embodiments described herein are not limited to elevatorsystems, such as that shown in FIG. 1. In one example, embodimentsdisclosed herein may be applicable conveyance systems such as anelevator system 101 and a conveyance apparatus of the conveyance systemsuch as an elevator car 103 of the elevator system 101. In anotherexample, embodiments disclosed herein may be applicable conveyancesystems such as an escalator system and a conveyance apparatus of theconveyance system such as a moving stair of the escalator system.

Referring now to FIGS. 2-6 with continued reference to FIG. 1, a view ofa wireless power transfer system 200 for use with the elevator system101 of FIG. 1 is illustrated, in accordance with an embodiment of thepresent disclosure. It should be appreciated that, although particularsystems are separately defined in the schematic block diagrams, each orany of the systems may be otherwise combined or separated via hardwareand/or software. The wireless power transfer system 200 may include apower source 210, an AC/DC power converter 220, a power managementsystem 230, a wireless electrical power transmitter 240, a wirelesselectrical power receiver 250, an energy storage device managementsystem 260, and an energy storage device 270. An energy storage device270 may not be required if energy harvesting is used.

The power source 210 may be a stationary power source, such as, forexample electrical grid power, wind power, solar power, generator power,etc. The power source 210 may provide electrical power using alternatingcurrent (AC). The AC electrical power provided by the power source 210may be three phase AC for higher power greater than about 3 kW. TheAC/DC power converter 220 is configured to receive the AC electric powerfrom the power source 210 and convert the AC electrical power into DCelectrical power. The AC/DC power converter 220 is electricallyconnected to the power source 210. The electrical connection between theAC/DC power converter 220 and the power source 210 may be hardwired.

The power management system 230 is electrically connected to the AC/DCpower converter 220. The electrical connection between the powermanagement system 230 and the AC/DC power converter 220 may behardwired. The power management system 230 operates as a powercontroller to supply the power needs of the elevator car 103 proximate afirst location A1 and a second location A2. The first location A1 andthe second location A1 may be planes through the elevator shaft 117about perpendicular to an axis X1 that runs parallel to the elevatorshaft 117. The power management system 230 controls switching,directing, or redirecting power to the elevator car 103 through one ormore wireless power transmitters 240 as needed to satisfy the powerrequirements of the elevator car 103. Switching, directing, andredirecting may readily be accomplished employing a bus controlswitching device 232 of the power management system 230. The bus controlswitching device 232 may include, but not be limited to,electromechanical and solid state semiconductor switching devicesincluding relays, contactors, solid state contactors as well assemiconductor switching devices such as transistors, FETs, MOSFETS,IGBT's, thyristors, SCR's, and the like. In addition, to facilitate andimplement the functionality of the power management system 230, thevoltages and frequencies of the power supplied by the power source 210may be adjusted by the bus control switching device 232. The wirelesspower transmitters 240 may later adjust the frequency of the electricalpower to satisfy the needs of the elevator car 103. The wirelesselectrical power transmitter 240 may be intelligent enough to identifythe resonant frequency and power flow between and adjust frequencies tomeet requested power flow. The intelligence could also be with thewireless electrical power transmitter 240 in the sensing of the currentbeing transmitted.

The wireless power transfer system 200 may include one or more wirelesselectrical power transmitters 240, as shown in FIG. 2. The electricalpower transmitters 240 are electrically connected to the powermanagement system 230. The electrical connection between the electricalpower transmitter 240 and the power management system 230 may behardwired. The wireless electrical power transmitter 240 may be locatedat different locations along a side of the elevator shaft 117. The sidemay be a wall 117 a of the elevator shaft 117, as shown in FIG. 2. Inthe example shown in FIG. 2, two wireless electrical power transmitter240 are illustrated, including a wireless electrical power transmitter240 is located at a first location A1 along a wall 117 a of the elevatorshaft 117 and a wireless electrical power transmitter 240 is located ata second location A2 along a wall 117 a of the elevator shaft 117. Thewireless electrical power transmitter 240 may be attached to the wall117 a or embedded in the wall 117 a, or in any other desiredarrangement. The wireless electrical power transmitter 240 may include aselected number of electrical coils configured to generate a magneticfield 242 when electrical power is run through the electrical coils. Theelectrical coils of the wireless electrical power transmitter 240 arenot shown in FIG. 2 for simplification of the illustration.

The wireless power transfer system 200 may include one or more wirelesselectrical power receivers 250, as shown in FIG. 2. The wirelesselectrical wireless electrical power receivers 250 may be located atdifferent locations along a surface 103 a of the elevator car 103. Thewireless electrical power receivers 250 may be attached to the surface103 a of the elevator car 103 or embedded in the surface 103 a of theelevator car 103. The surface 103 a of the elevator car 103 is locatedopposite the wall 117 a of the elevator shaft 117 where the wirelesselectrical power transmitter 240 is located. Therefore, when theelevator car 103 and the wireless electrical power receivers 250 arelocated at the first location A1, the wireless electrical powerreceivers 250 and the wireless electrical power transmitter 240 at thefirst location A1 are in a facing spaced relationship and a gap G1 isformed therebetween. The gap G1 is formed between the wirelesselectrical power receivers 250 and the wireless electrical powertransmitter 240 at the first location A1, as shown in FIG. 2. Likewise,when the elevator car 103 and the wireless electrical power receivers250 are located at the second location A2, the wireless electrical powerreceivers 250 and the wireless electrical power transmitter 240 at thesecond location A2 are in a facing spaced relationship. The gap G1 willalso be present between the wireless electrical power receivers 250 andthe wireless electrical power transmitter 240 at the second location A2.The wireless electrical power receivers 250 may include a selectednumber of electrical coils configured to generate an electric power inresponse to the magnetic field 242 when the wireless electrical powerreceiver 250 is within the transmission range of the magnetic field 242generated by the wireless electrical power transmitter 240. Theelectrical coils of the wireless electrical power receiver 250 are notshown in FIG. 2 for simplification of the illustration.

The electrical power receivers 250 are electrically connected to theenergy storage device management system 260. The electrical connectionbetween the electrical power receiver 250 and the energy storage devicemanagement system 260 may be hardwired or wireless. The energy storagedevice management system 260 is configured to condition the electricalpower received from the electrical power receivers 250 and transfer theelectrical power to the energy storage device 270 as needed. The energystorage device management system 260 monitors operation data of theenergy storage device 270 including but not limited to the state ofcharge of the energy storage device 270, a state of health of the energystorage device 270, and a temperature of the energy storage device 270.Examples of the energy storage device 270 may include a battery system(e.g., a battery or bank of batteries), fuel cells, flow battery, andothers devices capable of storing and outputting electric energy thatmay be DC. In one embodiment, the energy storage device 270 may storepotential energy rather than electrical energy and that potential energymay be utilized to create electrical energy for the elevator car 103 a,130 b. The energy storage device 270 may include a battery system, whichmay employ multiple batteries organized into battery banks. The energystorage device 270 is electrically connected to the elevator car 103.The electrical connection between the energy storage device 270 and theelevator car 103 may be hardwired. The energy storage device 270 maypower lighting inside the elevator car 103, fans, an emergency phone,climate controls, communication system, and/or the operating panel ofthe elevator car 103. The operating panel of the elevator car 103 mayconsists of floor buttons, a door open button, a door close button,other similar buttons, or may be a touchscreen.

As discussed above, the wireless electrical power receivers 250 mayinclude a selected number of electrical coils configured to generate anelectric power in response to the magnetic field 242 when the wirelesselectrical power receiver 250 is within the transmission range of themagnetic field 242 generated by the wireless electrical powertransmitter 240. The transmission range may be measured along verticalaxis X1 of the shaft 117. The transmission range of wireless electricalpower from the wireless electrical power transmitter 240 to wirelesselectrical power receivers 250 via the magnetic field 242 may beenhanced using a magnetic field enhancer 300. For example, without themagnetic field enhancer 300 the transmission range of electrical powerfrom the wireless electrical power transmitter 240 to the wirelesselectrical power receiver 250 may occur over a distance equivalent to afirst transmission range D1, as shown in FIG. 3. Whereas with withoutthe magnetic field enhancer 300 the transmission range of electricalpower from the wireless electrical power transmitter 240 to the wirelesselectrical power receiver 250 may occur over a distance equivalent to asecond transmission range D2, as shown in FIG. 4. The secondtransmission range D2 is greater than the first transmission range D1.

The enhancer 300 may be removable from between the wireless electricalpower transmitter 240 and the wireless electrical power receiver 250. Inan embodiment, the magnetic field enhancer 300 may be located closer tothe wireless electrical power transmitter 240 than the wirelesselectrical power receiver 250, as shown in FIGS. 4-6. Alternatively, inanother embodiment, the magnetic field enhancer 300 may be locatedcloser to the wireless electrical power receiver 250 than the wirelesselectrical power transmitter 240. In an embodiment, the magnetic fieldenhancer 300 may be shaped to wrap at least partially around thewireless electrical power transmitter 240, such as, for example, a “C”shape as shown in FIG. 4. In another embodiment, the magnetic fieldenhancer 300 may be shaped to wrap at least partially around thewireless electrical power receiver 250, such as, for example, a “C”shape.

The magnetic field enhancer 300 may have a negative refractive indexthat bends the magnetic field 242 outward to extend the wireless powertransfer range. As shown in FIG. 5, the magnetic field enhancer 300 maybe composed of a metamaterial block 300 a configured to extend thewireless power transfer range. The metamaterial block 300 a may includeat least one of a spiral resonator 310 and a split ring resonator 320.Alternatively, as shown in FIG. 6, the magnetic field enhancer 300 maybe also composed of an array of resonators 330 at 300 b. The array ofresonators 330 are configured to extend the transfer range of wirelesselectrical power.

Advantageously, the second transmission range D2 being greater than thefirst transmission range D1 creates an increased transmission range thatallows more time for the transmission of electrical power from thewireless electrical power transmitter 240 to the wireless electricalpower receiver 250 as the wireless electrical power receiver 250 movespast the wireless electrical power transmitter 240. This increasedtransmission range allows either more electric power to be transferredor the same electrical power to be transferred.

Additionally, due to limited range of the first transmission range D1,the wireless electrical power transmitter 240 of FIG. 3 may only be ableto transfer electrical power under static operation (i.e., when theelevator car 103 is stopped), and hence, the charging time during at theelevator landings 125 is limited by the stop time (e.g., about 10seconds). Advantageously, by extending the transmission range from thefirst transmission range D1 to the second transmission rang D2, theelectrical power transfer can be carried out when the elevator car 103is approaching and/or leaving the location A1, A2 of the wirelesselectrical power transmitter 240, thus increasing the total charge time.Additionally, the increased total charge time may reduce the sizingrequirements of the energy storage device 270 and also power transferratings, thus reducing cost while increasing performance of the wirelesspower transfer system 200. Also advantageously, utilizing a magneticfield enhancer 300 can achieve robust wireless power transfer operationunder a variation of the air-gap sizes and other changing conditions(e.g., load, input voltage) to maintain a desired output to the elevatorcar 103, which enables efficient operation operations of the elevatorsystem 101 and simplifies installation efforts by allowing largermechanical tolerances.

The term “about” is intended to include the degree of error associatedwith measurement of the particular quantity and/or manufacturingtolerances based upon the equipment available at the time of filing theapplication.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentdisclosure. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,element components, and/or groups thereof.

Those of skill in the art will appreciate that various exampleembodiments are shown and described herein, each having certain featuresin the particular embodiments, but the present disclosure is not thuslimited. Rather, the present disclosure can be modified to incorporateany number of variations, alterations, substitutions, combinations,sub-combinations, or equivalent arrangements not heretofore described,but which are commensurate with the scope of the present disclosure.Additionally, while various embodiments of the present disclosure havebeen described, it is to be understood that aspects of the presentdisclosure may include only some of the described embodiments.Accordingly, the present disclosure is not to be seen as limited by theforegoing description, but is only limited by the scope of the appendedclaims.

What is claimed is:
 1. A wireless power transfer system for wirelesslypowering a conveyance apparatus of a conveyance system, the wirelesspower transfer system comprising: a wireless electrical powertransmitter located along a side of the conveyance system in a firstlocation, the side being stationary; a wireless electrical powerreceiver located along a surface of the conveyance apparatus oppositethe side, the wireless electrical power receiver and the wirelesselectrical power transmitter being in a facing spaced relationshipdefining a gap therebetween when the wireless electrical power receiveris located at the first location; and a magnetic field enchanter locatedwithin the gap, the magnetic field enhancer being configured to extend awireless power transfer range of the wireless electrical powertransmitter, wherein the magnetic field enhancer is shaped to wrap atleast partially around at least two sides of the wireless electricalpower transmitter.
 2. The wireless power transfer system of claim 1,wherein the conveyance system is an elevator system and the conveyanceapparatus is an elevator car.
 3. The wireless power transfer system ofclaim 2, wherein the side is a wall of an elevator shaft of the elevatorsystem.
 4. The wireless power transfer system of claim 1, wherein themagnetic field enhancer further comprises a metamaterial block.
 5. Thewireless power transfer system of claim 4, wherein the metamaterialblock includes at least one of a spiral resonator and a split ringresonator.
 6. The wireless power transfer system of claim 1, wherein themagnetic field enhancer further comprises an array of resonators.
 7. Thewireless power transfer system of claim 1, wherein the magnetic fieldenhancer is located closer to the wireless electrical power transmitterthan the wireless electrical power receiver.
 8. The wireless powertransfer system of claim 1, wherein the magnetic field enhancer islocated closer to the wireless electrical power receiver than thewireless electrical power transmitter.
 9. A conveyance system,comprising a conveyance apparatus; and a wireless power transfer systemfor wirelessly powering the conveyance apparatus of the conveyancesystem, the wireless power transfer system comprising: a wirelesselectrical power transmitter located along a side of the conveyancesystem in a first location, the side being stationary; a wirelesselectrical power receiver located along a surface of the conveyanceapparatus opposite the side, the wireless electrical power receiver andthe wireless electrical power transmitter being in a facing spacedrelationship defining a gap therebetween when the wireless electricalpower receiver is located at the first location; and a magnetic fieldenhancer located within the gap, the magnetic field enhancer beingconfigured to extend a wireless power transfer range of the wirelesselectrical power transmitter, wherein the magnetic field enhancer isshaped to wrap at least partially around at least two sides of thewarless electrical power transmitter.
 10. The conveyance system of claim9, wherein the conveyance system is an elevator system and theconveyance apparatus is an elevator car.
 11. The conveyance system ofclaim 10, wherein the side is a wall of an elevator shaft of theelevator system.
 12. The conveyance system of claim 9, wherein themagnetic field enhancer further comprises a metamaterial block.
 13. Theconveyance system of claim 12, wherein the metamaterial block includesat least one of a spiral resonator and a split ring resonator.
 14. Theconveyance system of claim 9, wherein the magnetic field enhancerfurther comprises an array of resonators.
 15. The conveyance system ofclaim 9, wherein the magnetic field enhancer is located closer to thewireless electrical power transmitter than the wireless electrical powerreceiver.
 16. The conveyance system of claim 9, wherein the magneticfield enhancer is located closer to the wireless electrical powerreceiver than the wireless electrical power transmitter.